You may need to change Sendmail to run as another user instead of root. In order to do this, run the commands below. We are using sendmail for the user, and sendmail for group. Make sure to stop the sendmail service by using the service sendmail stop command. You may also need to kill any running processes by using the killall sendmail command.
groupadd -g 24 sendmail
useradd -u 24 -g 24 -M -d /var/spool/mqueue \-s /dev/null sendmail
chown -R sendmail:sendmail /var/spool/mqueue
chmod 700 /var/spool/mqueue
chgrp -R sendmail...

Recently we ran into some issues with some of our old sites that are relying on the register_globals for variable access after upgrading to PHP 5.4 which wisely no longer supports this kind of setup. Using globals in this fashion is a horrible practice, but sometimes you gotta maintain some legacy code.
To use global variables you can add a line of code to htaccess that will run a “globalizer” file before loading the main page on every page load and extract the required variables.
globalizer.php file
<!--?php...

If you need detailed information about Apache processes and which site is using them. Edit your httpd_conf file, and change the following directives:
<Location /secret-name-server-status>
SetHandler server-status
Order deny,allow
Deny from none
Allow from all
</Location>
You can set Allow from [specific IP address or range] for greater security
Also change un-comment the # by removing the # character:
ExtendedStatus On
Then, go to Listen On directives, and add an unused port:
Listen 4567
Save changes, restart apache...

If your server needs to have multiple IP addresses on the same physical NIC, you need to create multiple Virtual Interfaces. For example, the default eth0 configuration will have an IP address from one network IP block, but you need to add another IP address, from a different IP block, with a different gateway.
Here are the steps to add multiple IP addresses with multiple default gateways on the same physical NIC:
Create a separate file in /etc/sysconfig/network-scripts called eth0:1 or eth0:2, etc. Increment for each new IP address. ...

If you need to copy a file into every sub-directory within a directory, navigate there, and run this command:
find -type d -maxdepth 1 -print0 | xargs -0 -n1 cp .htaccess
The maxdepth 1 switch allows you to go only 1 subdirectory deep, you can change it to 2, or 3 or leave it out altogether to copy into every subdirectory, regardless of depth. You can copy any file, not just .htaccess this way.
find -type d -print0 | xargs -0 -n1 cp .htaccess
This can be especially useful for WordPress media files and upload directories organized by...